Commit | Line | Data |
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09c434b8 | 1 | // SPDX-License-Identifier: GPL-2.0-only |
09e410de JE |
2 | /* |
3 | * xt_hashlimit - Netfilter module to limit the number of packets per time | |
3ad2f3fb | 4 | * separately for each hashbucket (sourceip/sourceport/dstip/dstport) |
1da177e4 | 5 | * |
09e410de | 6 | * (C) 2003-2004 by Harald Welte <laforge@netfilter.org> |
f229f6ce | 7 | * (C) 2006-2012 Patrick McHardy <kaber@trash.net> |
09e410de | 8 | * Copyright © CC Computer Consultants GmbH, 2007 - 2008 |
1da177e4 LT |
9 | * |
10 | * Development of this code was funded by Astaro AG, http://www.astaro.com/ | |
1da177e4 | 11 | */ |
8bee4bad | 12 | #define pr_fmt(fmt) KBUILD_MODNAME ": " fmt |
1da177e4 | 13 | #include <linux/module.h> |
1da177e4 LT |
14 | #include <linux/spinlock.h> |
15 | #include <linux/random.h> | |
16 | #include <linux/jhash.h> | |
17 | #include <linux/slab.h> | |
18 | #include <linux/vmalloc.h> | |
1da177e4 LT |
19 | #include <linux/proc_fs.h> |
20 | #include <linux/seq_file.h> | |
21 | #include <linux/list.h> | |
39b46fc6 | 22 | #include <linux/skbuff.h> |
d7fe0f24 | 23 | #include <linux/mm.h> |
39b46fc6 PM |
24 | #include <linux/in.h> |
25 | #include <linux/ip.h> | |
c0cd1156 | 26 | #if IS_ENABLED(CONFIG_IP6_NF_IPTABLES) |
39b46fc6 | 27 | #include <linux/ipv6.h> |
193b23c5 | 28 | #include <net/ipv6.h> |
7b21e09d ED |
29 | #endif |
30 | ||
457c4cbc | 31 | #include <net/net_namespace.h> |
e89fc3f1 | 32 | #include <net/netns/generic.h> |
1da177e4 | 33 | |
39b46fc6 | 34 | #include <linux/netfilter/x_tables.h> |
1da177e4 | 35 | #include <linux/netfilter_ipv4/ip_tables.h> |
39b46fc6 | 36 | #include <linux/netfilter_ipv6/ip6_tables.h> |
14cc3e2b | 37 | #include <linux/mutex.h> |
90c4ae4e | 38 | #include <linux/kernel.h> |
c4a3922d | 39 | #include <linux/refcount.h> |
85cfbc25 JS |
40 | #include <uapi/linux/netfilter/xt_hashlimit.h> |
41 | ||
42 | #define XT_HASHLIMIT_ALL (XT_HASHLIMIT_HASH_DIP | XT_HASHLIMIT_HASH_DPT | \ | |
43 | XT_HASHLIMIT_HASH_SIP | XT_HASHLIMIT_HASH_SPT | \ | |
44 | XT_HASHLIMIT_INVERT | XT_HASHLIMIT_BYTES |\ | |
45 | XT_HASHLIMIT_RATE_MATCH) | |
1da177e4 LT |
46 | |
47 | MODULE_LICENSE("GPL"); | |
48 | MODULE_AUTHOR("Harald Welte <laforge@netfilter.org>"); | |
408ffaa4 | 49 | MODULE_AUTHOR("Jan Engelhardt <jengelh@medozas.de>"); |
2ae15b64 | 50 | MODULE_DESCRIPTION("Xtables: per hash-bucket rate-limit match"); |
39b46fc6 PM |
51 | MODULE_ALIAS("ipt_hashlimit"); |
52 | MODULE_ALIAS("ip6t_hashlimit"); | |
1da177e4 | 53 | |
e89fc3f1 AD |
54 | struct hashlimit_net { |
55 | struct hlist_head htables; | |
56 | struct proc_dir_entry *ipt_hashlimit; | |
57 | struct proc_dir_entry *ip6t_hashlimit; | |
58 | }; | |
59 | ||
c7d03a00 | 60 | static unsigned int hashlimit_net_id; |
e89fc3f1 AD |
61 | static inline struct hashlimit_net *hashlimit_pernet(struct net *net) |
62 | { | |
63 | return net_generic(net, hashlimit_net_id); | |
64 | } | |
65 | ||
1da177e4 | 66 | /* need to declare this at the top */ |
fd24de89 CH |
67 | static const struct seq_operations dl_seq_ops_v2; |
68 | static const struct seq_operations dl_seq_ops_v1; | |
69 | static const struct seq_operations dl_seq_ops; | |
1da177e4 LT |
70 | |
71 | /* hash table crap */ | |
1da177e4 | 72 | struct dsthash_dst { |
39b46fc6 PM |
73 | union { |
74 | struct { | |
75 | __be32 src; | |
76 | __be32 dst; | |
77 | } ip; | |
c0cd1156 | 78 | #if IS_ENABLED(CONFIG_IP6_NF_IPTABLES) |
39b46fc6 PM |
79 | struct { |
80 | __be32 src[4]; | |
81 | __be32 dst[4]; | |
82 | } ip6; | |
7b21e09d | 83 | #endif |
09e410de | 84 | }; |
6a19d614 AV |
85 | __be16 src_port; |
86 | __be16 dst_port; | |
1da177e4 LT |
87 | }; |
88 | ||
89 | struct dsthash_ent { | |
90 | /* static / read-only parts in the beginning */ | |
91 | struct hlist_node node; | |
92 | struct dsthash_dst dst; | |
93 | ||
94 | /* modified structure members in the end */ | |
02e4eb75 | 95 | spinlock_t lock; |
1da177e4 LT |
96 | unsigned long expires; /* precalculated expiry time */ |
97 | struct { | |
98 | unsigned long prev; /* last modification */ | |
bea74641 VP |
99 | union { |
100 | struct { | |
101 | u_int64_t credit; | |
102 | u_int64_t credit_cap; | |
103 | u_int64_t cost; | |
104 | }; | |
105 | struct { | |
106 | u_int32_t interval, prev_window; | |
107 | u_int64_t current_rate; | |
108 | u_int64_t rate; | |
109 | int64_t burst; | |
110 | }; | |
111 | }; | |
1da177e4 | 112 | } rateinfo; |
02e4eb75 | 113 | struct rcu_head rcu; |
1da177e4 LT |
114 | }; |
115 | ||
39b46fc6 | 116 | struct xt_hashlimit_htable { |
1da177e4 | 117 | struct hlist_node node; /* global list of all htables */ |
c4a3922d | 118 | refcount_t use; |
76108cea | 119 | u_int8_t family; |
89bc7a0f | 120 | bool rnd_initialized; |
1da177e4 | 121 | |
bea74641 | 122 | struct hashlimit_cfg3 cfg; /* config */ |
1da177e4 LT |
123 | |
124 | /* used internally */ | |
125 | spinlock_t lock; /* lock for list_head */ | |
126 | u_int32_t rnd; /* random seed for hash */ | |
39b46fc6 | 127 | unsigned int count; /* number entries in table */ |
7bd8490e | 128 | struct delayed_work gc_work; |
1da177e4 LT |
129 | |
130 | /* seq_file stuff */ | |
131 | struct proc_dir_entry *pde; | |
14b872f0 | 132 | const char *name; |
e89fc3f1 | 133 | struct net *net; |
1da177e4 | 134 | |
6daf1414 | 135 | struct hlist_head hash[]; /* hashtable itself */ |
1da177e4 LT |
136 | }; |
137 | ||
11d5f157 | 138 | static int |
bea74641 | 139 | cfg_copy(struct hashlimit_cfg3 *to, const void *from, int revision) |
11d5f157 VP |
140 | { |
141 | if (revision == 1) { | |
bea74641 | 142 | struct hashlimit_cfg1 *cfg = (struct hashlimit_cfg1 *)from; |
11d5f157 VP |
143 | |
144 | to->mode = cfg->mode; | |
145 | to->avg = cfg->avg; | |
146 | to->burst = cfg->burst; | |
147 | to->size = cfg->size; | |
148 | to->max = cfg->max; | |
149 | to->gc_interval = cfg->gc_interval; | |
150 | to->expire = cfg->expire; | |
151 | to->srcmask = cfg->srcmask; | |
152 | to->dstmask = cfg->dstmask; | |
153 | } else if (revision == 2) { | |
bea74641 VP |
154 | struct hashlimit_cfg2 *cfg = (struct hashlimit_cfg2 *)from; |
155 | ||
156 | to->mode = cfg->mode; | |
157 | to->avg = cfg->avg; | |
158 | to->burst = cfg->burst; | |
159 | to->size = cfg->size; | |
160 | to->max = cfg->max; | |
161 | to->gc_interval = cfg->gc_interval; | |
162 | to->expire = cfg->expire; | |
163 | to->srcmask = cfg->srcmask; | |
164 | to->dstmask = cfg->dstmask; | |
165 | } else if (revision == 3) { | |
166 | memcpy(to, from, sizeof(struct hashlimit_cfg3)); | |
11d5f157 VP |
167 | } else { |
168 | return -EINVAL; | |
169 | } | |
170 | ||
171 | return 0; | |
172 | } | |
173 | ||
2eff25c1 | 174 | static DEFINE_MUTEX(hashlimit_mutex); /* protects htables list */ |
e18b890b | 175 | static struct kmem_cache *hashlimit_cachep __read_mostly; |
1da177e4 | 176 | |
1d93a9cb | 177 | static inline bool dst_cmp(const struct dsthash_ent *ent, |
a47362a2 | 178 | const struct dsthash_dst *b) |
1da177e4 | 179 | { |
39b46fc6 | 180 | return !memcmp(&ent->dst, b, sizeof(ent->dst)); |
1da177e4 LT |
181 | } |
182 | ||
39b46fc6 PM |
183 | static u_int32_t |
184 | hash_dst(const struct xt_hashlimit_htable *ht, const struct dsthash_dst *dst) | |
1da177e4 | 185 | { |
e2f82ac3 ED |
186 | u_int32_t hash = jhash2((const u32 *)dst, |
187 | sizeof(*dst)/sizeof(u32), | |
188 | ht->rnd); | |
189 | /* | |
190 | * Instead of returning hash % ht->cfg.size (implying a divide) | |
191 | * we return the high 32 bits of the (hash * ht->cfg.size) that will | |
192 | * give results between [0 and cfg.size-1] and same hash distribution, | |
193 | * but using a multiply, less expensive than a divide | |
194 | */ | |
8fc54f68 | 195 | return reciprocal_scale(hash, ht->cfg.size); |
1da177e4 LT |
196 | } |
197 | ||
39b46fc6 | 198 | static struct dsthash_ent * |
a47362a2 JE |
199 | dsthash_find(const struct xt_hashlimit_htable *ht, |
200 | const struct dsthash_dst *dst) | |
1da177e4 LT |
201 | { |
202 | struct dsthash_ent *ent; | |
1da177e4 LT |
203 | u_int32_t hash = hash_dst(ht, dst); |
204 | ||
39b46fc6 | 205 | if (!hlist_empty(&ht->hash[hash])) { |
b67bfe0d | 206 | hlist_for_each_entry_rcu(ent, &ht->hash[hash], node) |
02e4eb75 ED |
207 | if (dst_cmp(ent, dst)) { |
208 | spin_lock(&ent->lock); | |
1da177e4 | 209 | return ent; |
02e4eb75 | 210 | } |
39b46fc6 | 211 | } |
1da177e4 LT |
212 | return NULL; |
213 | } | |
214 | ||
215 | /* allocate dsthash_ent, initialize dst, put in htable and lock it */ | |
216 | static struct dsthash_ent * | |
a47362a2 | 217 | dsthash_alloc_init(struct xt_hashlimit_htable *ht, |
09181842 | 218 | const struct dsthash_dst *dst, bool *race) |
1da177e4 LT |
219 | { |
220 | struct dsthash_ent *ent; | |
221 | ||
02e4eb75 | 222 | spin_lock(&ht->lock); |
09181842 PNA |
223 | |
224 | /* Two or more packets may race to create the same entry in the | |
225 | * hashtable, double check if this packet lost race. | |
226 | */ | |
227 | ent = dsthash_find(ht, dst); | |
228 | if (ent != NULL) { | |
229 | spin_unlock(&ht->lock); | |
230 | *race = true; | |
231 | return ent; | |
232 | } | |
233 | ||
1da177e4 LT |
234 | /* initialize hash with random val at the time we allocate |
235 | * the first hashtable entry */ | |
02e4eb75 | 236 | if (unlikely(!ht->rnd_initialized)) { |
af07d241 | 237 | get_random_bytes(&ht->rnd, sizeof(ht->rnd)); |
89bc7a0f | 238 | ht->rnd_initialized = true; |
bf0857ea | 239 | } |
1da177e4 | 240 | |
39b46fc6 | 241 | if (ht->cfg.max && ht->count >= ht->cfg.max) { |
1da177e4 | 242 | /* FIXME: do something. question is what.. */ |
e87cc472 | 243 | net_err_ratelimited("max count of %u reached\n", ht->cfg.max); |
02e4eb75 ED |
244 | ent = NULL; |
245 | } else | |
246 | ent = kmem_cache_alloc(hashlimit_cachep, GFP_ATOMIC); | |
0a9ee813 | 247 | if (ent) { |
02e4eb75 ED |
248 | memcpy(&ent->dst, dst, sizeof(ent->dst)); |
249 | spin_lock_init(&ent->lock); | |
1da177e4 | 250 | |
02e4eb75 ED |
251 | spin_lock(&ent->lock); |
252 | hlist_add_head_rcu(&ent->node, &ht->hash[hash_dst(ht, dst)]); | |
253 | ht->count++; | |
254 | } | |
255 | spin_unlock(&ht->lock); | |
1da177e4 LT |
256 | return ent; |
257 | } | |
258 | ||
02e4eb75 ED |
259 | static void dsthash_free_rcu(struct rcu_head *head) |
260 | { | |
261 | struct dsthash_ent *ent = container_of(head, struct dsthash_ent, rcu); | |
262 | ||
263 | kmem_cache_free(hashlimit_cachep, ent); | |
264 | } | |
265 | ||
39b46fc6 PM |
266 | static inline void |
267 | dsthash_free(struct xt_hashlimit_htable *ht, struct dsthash_ent *ent) | |
1da177e4 | 268 | { |
02e4eb75 | 269 | hlist_del_rcu(&ent->node); |
c8d1da40 | 270 | call_rcu(&ent->rcu, dsthash_free_rcu); |
39b46fc6 | 271 | ht->count--; |
1da177e4 | 272 | } |
7bd8490e | 273 | static void htable_gc(struct work_struct *work); |
1da177e4 | 274 | |
bea74641 | 275 | static int htable_create(struct net *net, struct hashlimit_cfg3 *cfg, |
11d5f157 VP |
276 | const char *name, u_int8_t family, |
277 | struct xt_hashlimit_htable **out_hinfo, | |
278 | int revision) | |
09e410de | 279 | { |
e89fc3f1 | 280 | struct hashlimit_net *hashlimit_net = hashlimit_pernet(net); |
09e410de | 281 | struct xt_hashlimit_htable *hinfo; |
fd24de89 | 282 | const struct seq_operations *ops; |
11d5f157 | 283 | unsigned int size, i; |
ca79b0c2 | 284 | unsigned long nr_pages = totalram_pages(); |
11d5f157 | 285 | int ret; |
09e410de | 286 | |
11d5f157 VP |
287 | if (cfg->size) { |
288 | size = cfg->size; | |
09e410de | 289 | } else { |
3d6357de | 290 | size = (nr_pages << PAGE_SHIFT) / 16384 / |
05d0eae7 | 291 | sizeof(struct hlist_head); |
3d6357de | 292 | if (nr_pages > 1024 * 1024 * 1024 / PAGE_SIZE) |
09e410de JE |
293 | size = 8192; |
294 | if (size < 16) | |
295 | size = 16; | |
296 | } | |
297 | /* FIXME: don't use vmalloc() here or anywhere else -HW */ | |
eabb4782 | 298 | hinfo = vmalloc(struct_size(hinfo, hash, size)); |
85bc3f38 | 299 | if (hinfo == NULL) |
4a5a5c73 | 300 | return -ENOMEM; |
11d5f157 | 301 | *out_hinfo = hinfo; |
09e410de JE |
302 | |
303 | /* copy match config into hashtable config */ | |
bea74641 | 304 | ret = cfg_copy(&hinfo->cfg, (void *)cfg, 3); |
b4e955e9 TY |
305 | if (ret) { |
306 | vfree(hinfo); | |
11d5f157 | 307 | return ret; |
b4e955e9 | 308 | } |
11d5f157 | 309 | |
09e410de JE |
310 | hinfo->cfg.size = size; |
311 | if (hinfo->cfg.max == 0) | |
312 | hinfo->cfg.max = 8 * hinfo->cfg.size; | |
313 | else if (hinfo->cfg.max < hinfo->cfg.size) | |
314 | hinfo->cfg.max = hinfo->cfg.size; | |
315 | ||
316 | for (i = 0; i < hinfo->cfg.size; i++) | |
317 | INIT_HLIST_HEAD(&hinfo->hash[i]); | |
318 | ||
c4a3922d | 319 | refcount_set(&hinfo->use, 1); |
09e410de JE |
320 | hinfo->count = 0; |
321 | hinfo->family = family; | |
89bc7a0f | 322 | hinfo->rnd_initialized = false; |
11d5f157 | 323 | hinfo->name = kstrdup(name, GFP_KERNEL); |
14b872f0 AV |
324 | if (!hinfo->name) { |
325 | vfree(hinfo); | |
326 | return -ENOMEM; | |
327 | } | |
09e410de JE |
328 | spin_lock_init(&hinfo->lock); |
329 | ||
bea74641 VP |
330 | switch (revision) { |
331 | case 1: | |
fd24de89 | 332 | ops = &dl_seq_ops_v1; |
bea74641 VP |
333 | break; |
334 | case 2: | |
fd24de89 | 335 | ops = &dl_seq_ops_v2; |
bea74641 VP |
336 | break; |
337 | default: | |
fd24de89 | 338 | ops = &dl_seq_ops; |
bea74641 VP |
339 | } |
340 | ||
fd24de89 | 341 | hinfo->pde = proc_create_seq_data(name, 0, |
ee999d8b | 342 | (family == NFPROTO_IPV4) ? |
e89fc3f1 | 343 | hashlimit_net->ipt_hashlimit : hashlimit_net->ip6t_hashlimit, |
fd24de89 | 344 | ops, hinfo); |
09e410de | 345 | if (hinfo->pde == NULL) { |
14b872f0 | 346 | kfree(hinfo->name); |
09e410de | 347 | vfree(hinfo); |
4a5a5c73 | 348 | return -ENOMEM; |
09e410de | 349 | } |
e89fc3f1 | 350 | hinfo->net = net; |
09e410de | 351 | |
7bd8490e ED |
352 | INIT_DEFERRABLE_WORK(&hinfo->gc_work, htable_gc); |
353 | queue_delayed_work(system_power_efficient_wq, &hinfo->gc_work, | |
354 | msecs_to_jiffies(hinfo->cfg.gc_interval)); | |
09e410de | 355 | |
e89fc3f1 | 356 | hlist_add_head(&hinfo->node, &hashlimit_net->htables); |
09e410de JE |
357 | |
358 | return 0; | |
359 | } | |
360 | ||
28b3a427 | 361 | static void htable_selective_cleanup(struct xt_hashlimit_htable *ht, bool select_all) |
1da177e4 | 362 | { |
39b46fc6 | 363 | unsigned int i; |
1da177e4 | 364 | |
1da177e4 LT |
365 | for (i = 0; i < ht->cfg.size; i++) { |
366 | struct dsthash_ent *dh; | |
b67bfe0d | 367 | struct hlist_node *n; |
7bd8490e ED |
368 | |
369 | spin_lock_bh(&ht->lock); | |
b67bfe0d | 370 | hlist_for_each_entry_safe(dh, n, &ht->hash[i], node) { |
28b3a427 | 371 | if (time_after_eq(jiffies, dh->expires) || select_all) |
39b46fc6 | 372 | dsthash_free(ht, dh); |
1da177e4 | 373 | } |
7bd8490e ED |
374 | spin_unlock_bh(&ht->lock); |
375 | cond_resched(); | |
1da177e4 | 376 | } |
1da177e4 LT |
377 | } |
378 | ||
7bd8490e | 379 | static void htable_gc(struct work_struct *work) |
1da177e4 | 380 | { |
7bd8490e ED |
381 | struct xt_hashlimit_htable *ht; |
382 | ||
383 | ht = container_of(work, struct xt_hashlimit_htable, gc_work.work); | |
1da177e4 | 384 | |
28b3a427 | 385 | htable_selective_cleanup(ht, false); |
1da177e4 | 386 | |
7bd8490e ED |
387 | queue_delayed_work(system_power_efficient_wq, |
388 | &ht->gc_work, msecs_to_jiffies(ht->cfg.gc_interval)); | |
1da177e4 LT |
389 | } |
390 | ||
b4ef4ce0 | 391 | static void htable_remove_proc_entry(struct xt_hashlimit_htable *hinfo) |
1da177e4 | 392 | { |
e89fc3f1 AD |
393 | struct hashlimit_net *hashlimit_net = hashlimit_pernet(hinfo->net); |
394 | struct proc_dir_entry *parent; | |
395 | ||
e89fc3f1 AD |
396 | if (hinfo->family == NFPROTO_IPV4) |
397 | parent = hashlimit_net->ipt_hashlimit; | |
398 | else | |
399 | parent = hashlimit_net->ip6t_hashlimit; | |
32263dd1 | 400 | |
b4ef4ce0 | 401 | if (parent != NULL) |
14b872f0 | 402 | remove_proc_entry(hinfo->name, parent); |
b4ef4ce0 | 403 | } |
32263dd1 | 404 | |
e89fc3f1 AD |
405 | static struct xt_hashlimit_htable *htable_find_get(struct net *net, |
406 | const char *name, | |
76108cea | 407 | u_int8_t family) |
1da177e4 | 408 | { |
e89fc3f1 | 409 | struct hashlimit_net *hashlimit_net = hashlimit_pernet(net); |
39b46fc6 | 410 | struct xt_hashlimit_htable *hinfo; |
1da177e4 | 411 | |
b67bfe0d | 412 | hlist_for_each_entry(hinfo, &hashlimit_net->htables, node) { |
14b872f0 | 413 | if (!strcmp(name, hinfo->name) && |
39b46fc6 | 414 | hinfo->family == family) { |
c4a3922d | 415 | refcount_inc(&hinfo->use); |
1da177e4 LT |
416 | return hinfo; |
417 | } | |
418 | } | |
1da177e4 LT |
419 | return NULL; |
420 | } | |
421 | ||
39b46fc6 | 422 | static void htable_put(struct xt_hashlimit_htable *hinfo) |
1da177e4 | 423 | { |
c4a3922d | 424 | if (refcount_dec_and_mutex_lock(&hinfo->use, &hashlimit_mutex)) { |
1da177e4 | 425 | hlist_del(&hinfo->node); |
99b79c39 | 426 | htable_remove_proc_entry(hinfo); |
c4a3922d | 427 | mutex_unlock(&hashlimit_mutex); |
99b79c39 CW |
428 | |
429 | cancel_delayed_work_sync(&hinfo->gc_work); | |
430 | htable_selective_cleanup(hinfo, true); | |
431 | kfree(hinfo->name); | |
432 | vfree(hinfo); | |
1da177e4 LT |
433 | } |
434 | } | |
435 | ||
1da177e4 LT |
436 | /* The algorithm used is the Simple Token Bucket Filter (TBF) |
437 | * see net/sched/sch_tbf.c in the linux source tree | |
438 | */ | |
439 | ||
440 | /* Rusty: This is my (non-mathematically-inclined) understanding of | |
441 | this algorithm. The `average rate' in jiffies becomes your initial | |
442 | amount of credit `credit' and the most credit you can ever have | |
443 | `credit_cap'. The `peak rate' becomes the cost of passing the | |
444 | test, `cost'. | |
445 | ||
446 | `prev' tracks the last packet hit: you gain one credit per jiffy. | |
447 | If you get credit balance more than this, the extra credit is | |
448 | discarded. Every time the match passes, you lose `cost' credits; | |
449 | if you don't have that many, the test fails. | |
450 | ||
451 | See Alexey's formal explanation in net/sched/sch_tbf.c. | |
452 | ||
453 | To get the maximum range, we multiply by this factor (ie. you get N | |
454 | credits per jiffy). We want to allow a rate as low as 1 per day | |
455 | (slowest userspace tool allows), which means | |
456 | CREDITS_PER_JIFFY*HZ*60*60*24 < 2^32 ie. | |
457 | */ | |
0dc60a45 | 458 | #define MAX_CPJ_v1 (0xFFFFFFFF / (HZ*60*60*24)) |
1b203c13 | 459 | #define MAX_CPJ (0xFFFFFFFFFFFFFFFFULL / (HZ*60*60*24)) |
1da177e4 LT |
460 | |
461 | /* Repeated shift and or gives us all 1s, final shift and add 1 gives | |
462 | * us the power of 2 below the theoretical max, so GCC simply does a | |
463 | * shift. */ | |
464 | #define _POW2_BELOW2(x) ((x)|((x)>>1)) | |
465 | #define _POW2_BELOW4(x) (_POW2_BELOW2(x)|_POW2_BELOW2((x)>>2)) | |
466 | #define _POW2_BELOW8(x) (_POW2_BELOW4(x)|_POW2_BELOW4((x)>>4)) | |
467 | #define _POW2_BELOW16(x) (_POW2_BELOW8(x)|_POW2_BELOW8((x)>>8)) | |
468 | #define _POW2_BELOW32(x) (_POW2_BELOW16(x)|_POW2_BELOW16((x)>>16)) | |
11d5f157 | 469 | #define _POW2_BELOW64(x) (_POW2_BELOW32(x)|_POW2_BELOW32((x)>>32)) |
1da177e4 | 470 | #define POW2_BELOW32(x) ((_POW2_BELOW32(x)>>1) + 1) |
11d5f157 | 471 | #define POW2_BELOW64(x) ((_POW2_BELOW64(x)>>1) + 1) |
1da177e4 | 472 | |
11d5f157 | 473 | #define CREDITS_PER_JIFFY POW2_BELOW64(MAX_CPJ) |
0dc60a45 | 474 | #define CREDITS_PER_JIFFY_v1 POW2_BELOW32(MAX_CPJ_v1) |
1da177e4 | 475 | |
0197dee7 FW |
476 | /* in byte mode, the lowest possible rate is one packet/second. |
477 | * credit_cap is used as a counter that tells us how many times we can | |
478 | * refill the "credits available" counter when it becomes empty. | |
479 | */ | |
480 | #define MAX_CPJ_BYTES (0xFFFFFFFF / HZ) | |
481 | #define CREDITS_PER_JIFFY_BYTES POW2_BELOW32(MAX_CPJ_BYTES) | |
482 | ||
483 | static u32 xt_hashlimit_len_to_chunks(u32 len) | |
484 | { | |
485 | return (len >> XT_HASHLIMIT_BYTE_SHIFT) + 1; | |
486 | } | |
487 | ||
1da177e4 | 488 | /* Precision saver. */ |
11d5f157 | 489 | static u64 user2credits(u64 user, int revision) |
1da177e4 | 490 | { |
ad5b5576 AB |
491 | u64 scale = (revision == 1) ? |
492 | XT_HASHLIMIT_SCALE : XT_HASHLIMIT_SCALE_v2; | |
493 | u64 cpj = (revision == 1) ? | |
494 | CREDITS_PER_JIFFY_v1 : CREDITS_PER_JIFFY; | |
1da177e4 | 495 | |
ad5b5576 AB |
496 | /* Avoid overflow: divide the constant operands first */ |
497 | if (scale >= HZ * cpj) | |
498 | return div64_u64(user, div64_u64(scale, HZ * cpj)); | |
499 | ||
500 | return user * div64_u64(HZ * cpj, scale); | |
1da177e4 LT |
501 | } |
502 | ||
0197dee7 | 503 | static u32 user2credits_byte(u32 user) |
1da177e4 | 504 | { |
0197dee7 FW |
505 | u64 us = user; |
506 | us *= HZ * CREDITS_PER_JIFFY_BYTES; | |
507 | return (u32) (us >> 32); | |
508 | } | |
509 | ||
bea74641 VP |
510 | static u64 user2rate(u64 user) |
511 | { | |
512 | if (user != 0) { | |
513 | return div64_u64(XT_HASHLIMIT_SCALE_v2, user); | |
514 | } else { | |
b2606644 FW |
515 | pr_info_ratelimited("invalid rate from userspace: %llu\n", |
516 | user); | |
bea74641 VP |
517 | return 0; |
518 | } | |
519 | } | |
520 | ||
90c4ae4e | 521 | static u64 user2rate_bytes(u32 user) |
bea74641 VP |
522 | { |
523 | u64 r; | |
524 | ||
90c4ae4e | 525 | r = user ? U32_MAX / user : U32_MAX; |
c47d36b3 | 526 | return (r - 1) << XT_HASHLIMIT_BYTE_SHIFT; |
bea74641 VP |
527 | } |
528 | ||
11d5f157 VP |
529 | static void rateinfo_recalc(struct dsthash_ent *dh, unsigned long now, |
530 | u32 mode, int revision) | |
0197dee7 FW |
531 | { |
532 | unsigned long delta = now - dh->rateinfo.prev; | |
11d5f157 | 533 | u64 cap, cpj; |
0197dee7 FW |
534 | |
535 | if (delta == 0) | |
536 | return; | |
537 | ||
bea74641 VP |
538 | if (revision >= 3 && mode & XT_HASHLIMIT_RATE_MATCH) { |
539 | u64 interval = dh->rateinfo.interval * HZ; | |
540 | ||
541 | if (delta < interval) | |
542 | return; | |
543 | ||
544 | dh->rateinfo.prev = now; | |
545 | dh->rateinfo.prev_window = | |
546 | ((dh->rateinfo.current_rate * interval) > | |
547 | (delta * dh->rateinfo.rate)); | |
548 | dh->rateinfo.current_rate = 0; | |
549 | ||
550 | return; | |
551 | } | |
552 | ||
39b46fc6 | 553 | dh->rateinfo.prev = now; |
0197dee7 FW |
554 | |
555 | if (mode & XT_HASHLIMIT_BYTES) { | |
11d5f157 | 556 | u64 tmp = dh->rateinfo.credit; |
0197dee7 FW |
557 | dh->rateinfo.credit += CREDITS_PER_JIFFY_BYTES * delta; |
558 | cap = CREDITS_PER_JIFFY_BYTES * HZ; | |
559 | if (tmp >= dh->rateinfo.credit) {/* overflow */ | |
560 | dh->rateinfo.credit = cap; | |
561 | return; | |
562 | } | |
563 | } else { | |
11d5f157 VP |
564 | cpj = (revision == 1) ? |
565 | CREDITS_PER_JIFFY_v1 : CREDITS_PER_JIFFY; | |
566 | dh->rateinfo.credit += delta * cpj; | |
0197dee7 FW |
567 | cap = dh->rateinfo.credit_cap; |
568 | } | |
569 | if (dh->rateinfo.credit > cap) | |
570 | dh->rateinfo.credit = cap; | |
39b46fc6 PM |
571 | } |
572 | ||
817e076f | 573 | static void rateinfo_init(struct dsthash_ent *dh, |
11d5f157 | 574 | struct xt_hashlimit_htable *hinfo, int revision) |
817e076f FW |
575 | { |
576 | dh->rateinfo.prev = jiffies; | |
bea74641 VP |
577 | if (revision >= 3 && hinfo->cfg.mode & XT_HASHLIMIT_RATE_MATCH) { |
578 | dh->rateinfo.prev_window = 0; | |
579 | dh->rateinfo.current_rate = 0; | |
580 | if (hinfo->cfg.mode & XT_HASHLIMIT_BYTES) { | |
90c4ae4e VP |
581 | dh->rateinfo.rate = |
582 | user2rate_bytes((u32)hinfo->cfg.avg); | |
bea74641 VP |
583 | if (hinfo->cfg.burst) |
584 | dh->rateinfo.burst = | |
585 | hinfo->cfg.burst * dh->rateinfo.rate; | |
586 | else | |
587 | dh->rateinfo.burst = dh->rateinfo.rate; | |
588 | } else { | |
589 | dh->rateinfo.rate = user2rate(hinfo->cfg.avg); | |
590 | dh->rateinfo.burst = | |
591 | hinfo->cfg.burst + dh->rateinfo.rate; | |
592 | } | |
593 | dh->rateinfo.interval = hinfo->cfg.interval; | |
594 | } else if (hinfo->cfg.mode & XT_HASHLIMIT_BYTES) { | |
0197dee7 FW |
595 | dh->rateinfo.credit = CREDITS_PER_JIFFY_BYTES * HZ; |
596 | dh->rateinfo.cost = user2credits_byte(hinfo->cfg.avg); | |
597 | dh->rateinfo.credit_cap = hinfo->cfg.burst; | |
598 | } else { | |
599 | dh->rateinfo.credit = user2credits(hinfo->cfg.avg * | |
11d5f157 VP |
600 | hinfo->cfg.burst, revision); |
601 | dh->rateinfo.cost = user2credits(hinfo->cfg.avg, revision); | |
0197dee7 FW |
602 | dh->rateinfo.credit_cap = dh->rateinfo.credit; |
603 | } | |
817e076f FW |
604 | } |
605 | ||
09e410de JE |
606 | static inline __be32 maskl(__be32 a, unsigned int l) |
607 | { | |
1b9b70ea | 608 | return l ? htonl(ntohl(a) & ~0 << (32 - l)) : 0; |
09e410de JE |
609 | } |
610 | ||
c0cd1156 | 611 | #if IS_ENABLED(CONFIG_IP6_NF_IPTABLES) |
09e410de JE |
612 | static void hashlimit_ipv6_mask(__be32 *i, unsigned int p) |
613 | { | |
614 | switch (p) { | |
1b9b70ea | 615 | case 0 ... 31: |
09e410de JE |
616 | i[0] = maskl(i[0], p); |
617 | i[1] = i[2] = i[3] = 0; | |
618 | break; | |
1b9b70ea | 619 | case 32 ... 63: |
09e410de JE |
620 | i[1] = maskl(i[1], p - 32); |
621 | i[2] = i[3] = 0; | |
622 | break; | |
1b9b70ea | 623 | case 64 ... 95: |
09e410de JE |
624 | i[2] = maskl(i[2], p - 64); |
625 | i[3] = 0; | |
8f599229 | 626 | break; |
1b9b70ea | 627 | case 96 ... 127: |
09e410de JE |
628 | i[3] = maskl(i[3], p - 96); |
629 | break; | |
630 | case 128: | |
631 | break; | |
632 | } | |
633 | } | |
3ed5df44 | 634 | #endif |
09e410de | 635 | |
39b46fc6 | 636 | static int |
a47362a2 JE |
637 | hashlimit_init_dst(const struct xt_hashlimit_htable *hinfo, |
638 | struct dsthash_dst *dst, | |
39b46fc6 PM |
639 | const struct sk_buff *skb, unsigned int protoff) |
640 | { | |
641 | __be16 _ports[2], *ports; | |
193b23c5 | 642 | u8 nexthdr; |
aca071c1 | 643 | int poff; |
39b46fc6 PM |
644 | |
645 | memset(dst, 0, sizeof(*dst)); | |
646 | ||
647 | switch (hinfo->family) { | |
ee999d8b | 648 | case NFPROTO_IPV4: |
39b46fc6 | 649 | if (hinfo->cfg.mode & XT_HASHLIMIT_HASH_DIP) |
09e410de JE |
650 | dst->ip.dst = maskl(ip_hdr(skb)->daddr, |
651 | hinfo->cfg.dstmask); | |
39b46fc6 | 652 | if (hinfo->cfg.mode & XT_HASHLIMIT_HASH_SIP) |
09e410de JE |
653 | dst->ip.src = maskl(ip_hdr(skb)->saddr, |
654 | hinfo->cfg.srcmask); | |
39b46fc6 PM |
655 | |
656 | if (!(hinfo->cfg.mode & | |
657 | (XT_HASHLIMIT_HASH_DPT | XT_HASHLIMIT_HASH_SPT))) | |
658 | return 0; | |
eddc9ec5 | 659 | nexthdr = ip_hdr(skb)->protocol; |
39b46fc6 | 660 | break; |
c0cd1156 | 661 | #if IS_ENABLED(CONFIG_IP6_NF_IPTABLES) |
ee999d8b | 662 | case NFPROTO_IPV6: |
412662d2 SR |
663 | { |
664 | __be16 frag_off; | |
665 | ||
09e410de JE |
666 | if (hinfo->cfg.mode & XT_HASHLIMIT_HASH_DIP) { |
667 | memcpy(&dst->ip6.dst, &ipv6_hdr(skb)->daddr, | |
668 | sizeof(dst->ip6.dst)); | |
669 | hashlimit_ipv6_mask(dst->ip6.dst, hinfo->cfg.dstmask); | |
670 | } | |
671 | if (hinfo->cfg.mode & XT_HASHLIMIT_HASH_SIP) { | |
672 | memcpy(&dst->ip6.src, &ipv6_hdr(skb)->saddr, | |
673 | sizeof(dst->ip6.src)); | |
674 | hashlimit_ipv6_mask(dst->ip6.src, hinfo->cfg.srcmask); | |
675 | } | |
39b46fc6 PM |
676 | |
677 | if (!(hinfo->cfg.mode & | |
678 | (XT_HASHLIMIT_HASH_DPT | XT_HASHLIMIT_HASH_SPT))) | |
679 | return 0; | |
193b23c5 | 680 | nexthdr = ipv6_hdr(skb)->nexthdr; |
75f2811c | 681 | protoff = ipv6_skip_exthdr(skb, sizeof(struct ipv6hdr), &nexthdr, &frag_off); |
193b23c5 | 682 | if ((int)protoff < 0) |
39b46fc6 PM |
683 | return -1; |
684 | break; | |
412662d2 | 685 | } |
39b46fc6 PM |
686 | #endif |
687 | default: | |
688 | BUG(); | |
689 | return 0; | |
690 | } | |
691 | ||
aca071c1 CG |
692 | poff = proto_ports_offset(nexthdr); |
693 | if (poff >= 0) { | |
694 | ports = skb_header_pointer(skb, protoff + poff, sizeof(_ports), | |
39b46fc6 | 695 | &_ports); |
aca071c1 | 696 | } else { |
39b46fc6 PM |
697 | _ports[0] = _ports[1] = 0; |
698 | ports = _ports; | |
39b46fc6 PM |
699 | } |
700 | if (!ports) | |
701 | return -1; | |
702 | if (hinfo->cfg.mode & XT_HASHLIMIT_HASH_SPT) | |
703 | dst->src_port = ports[0]; | |
704 | if (hinfo->cfg.mode & XT_HASHLIMIT_HASH_DPT) | |
705 | dst->dst_port = ports[1]; | |
706 | return 0; | |
1da177e4 LT |
707 | } |
708 | ||
0197dee7 FW |
709 | static u32 hashlimit_byte_cost(unsigned int len, struct dsthash_ent *dh) |
710 | { | |
711 | u64 tmp = xt_hashlimit_len_to_chunks(len); | |
712 | tmp = tmp * dh->rateinfo.cost; | |
713 | ||
714 | if (unlikely(tmp > CREDITS_PER_JIFFY_BYTES * HZ)) | |
715 | tmp = CREDITS_PER_JIFFY_BYTES * HZ; | |
716 | ||
717 | if (dh->rateinfo.credit < tmp && dh->rateinfo.credit_cap) { | |
718 | dh->rateinfo.credit_cap--; | |
719 | dh->rateinfo.credit = CREDITS_PER_JIFFY_BYTES * HZ; | |
720 | } | |
721 | return (u32) tmp; | |
722 | } | |
723 | ||
ccb79bdc | 724 | static bool |
11d5f157 VP |
725 | hashlimit_mt_common(const struct sk_buff *skb, struct xt_action_param *par, |
726 | struct xt_hashlimit_htable *hinfo, | |
bea74641 | 727 | const struct hashlimit_cfg3 *cfg, int revision) |
09e410de | 728 | { |
09e410de JE |
729 | unsigned long now = jiffies; |
730 | struct dsthash_ent *dh; | |
731 | struct dsthash_dst dst; | |
09181842 | 732 | bool race = false; |
11d5f157 | 733 | u64 cost; |
09e410de | 734 | |
f7108a20 | 735 | if (hashlimit_init_dst(hinfo, &dst, skb, par->thoff) < 0) |
09e410de JE |
736 | goto hotdrop; |
737 | ||
0b35f603 | 738 | local_bh_disable(); |
09e410de JE |
739 | dh = dsthash_find(hinfo, &dst); |
740 | if (dh == NULL) { | |
09181842 | 741 | dh = dsthash_alloc_init(hinfo, &dst, &race); |
09e410de | 742 | if (dh == NULL) { |
0b35f603 | 743 | local_bh_enable(); |
09e410de | 744 | goto hotdrop; |
09181842 PNA |
745 | } else if (race) { |
746 | /* Already got an entry, update expiration timeout */ | |
747 | dh->expires = now + msecs_to_jiffies(hinfo->cfg.expire); | |
11d5f157 | 748 | rateinfo_recalc(dh, now, hinfo->cfg.mode, revision); |
09181842 PNA |
749 | } else { |
750 | dh->expires = jiffies + msecs_to_jiffies(hinfo->cfg.expire); | |
11d5f157 | 751 | rateinfo_init(dh, hinfo, revision); |
09e410de | 752 | } |
09e410de JE |
753 | } else { |
754 | /* update expiration timeout */ | |
755 | dh->expires = now + msecs_to_jiffies(hinfo->cfg.expire); | |
11d5f157 | 756 | rateinfo_recalc(dh, now, hinfo->cfg.mode, revision); |
09e410de JE |
757 | } |
758 | ||
bea74641 VP |
759 | if (cfg->mode & XT_HASHLIMIT_RATE_MATCH) { |
760 | cost = (cfg->mode & XT_HASHLIMIT_BYTES) ? skb->len : 1; | |
761 | dh->rateinfo.current_rate += cost; | |
762 | ||
763 | if (!dh->rateinfo.prev_window && | |
764 | (dh->rateinfo.current_rate <= dh->rateinfo.burst)) { | |
765 | spin_unlock(&dh->lock); | |
de526f40 | 766 | local_bh_enable(); |
bea74641 VP |
767 | return !(cfg->mode & XT_HASHLIMIT_INVERT); |
768 | } else { | |
769 | goto overlimit; | |
770 | } | |
771 | } | |
772 | ||
11d5f157 | 773 | if (cfg->mode & XT_HASHLIMIT_BYTES) |
0197dee7 FW |
774 | cost = hashlimit_byte_cost(skb->len, dh); |
775 | else | |
776 | cost = dh->rateinfo.cost; | |
777 | ||
778 | if (dh->rateinfo.credit >= cost) { | |
09e410de | 779 | /* below the limit */ |
0197dee7 | 780 | dh->rateinfo.credit -= cost; |
02e4eb75 | 781 | spin_unlock(&dh->lock); |
0b35f603 | 782 | local_bh_enable(); |
11d5f157 | 783 | return !(cfg->mode & XT_HASHLIMIT_INVERT); |
09e410de JE |
784 | } |
785 | ||
bea74641 | 786 | overlimit: |
02e4eb75 | 787 | spin_unlock(&dh->lock); |
0b35f603 | 788 | local_bh_enable(); |
09e410de | 789 | /* default match is underlimit - so over the limit, we need to invert */ |
11d5f157 | 790 | return cfg->mode & XT_HASHLIMIT_INVERT; |
09e410de JE |
791 | |
792 | hotdrop: | |
b4ba2611 | 793 | par->hotdrop = true; |
09e410de JE |
794 | return false; |
795 | } | |
796 | ||
11d5f157 VP |
797 | static bool |
798 | hashlimit_mt_v1(const struct sk_buff *skb, struct xt_action_param *par) | |
799 | { | |
800 | const struct xt_hashlimit_mtinfo1 *info = par->matchinfo; | |
801 | struct xt_hashlimit_htable *hinfo = info->hinfo; | |
bea74641 | 802 | struct hashlimit_cfg3 cfg = {}; |
11d5f157 VP |
803 | int ret; |
804 | ||
805 | ret = cfg_copy(&cfg, (void *)&info->cfg, 1); | |
11d5f157 VP |
806 | if (ret) |
807 | return ret; | |
808 | ||
809 | return hashlimit_mt_common(skb, par, hinfo, &cfg, 1); | |
810 | } | |
811 | ||
812 | static bool | |
bea74641 | 813 | hashlimit_mt_v2(const struct sk_buff *skb, struct xt_action_param *par) |
11d5f157 VP |
814 | { |
815 | const struct xt_hashlimit_mtinfo2 *info = par->matchinfo; | |
816 | struct xt_hashlimit_htable *hinfo = info->hinfo; | |
bea74641 VP |
817 | struct hashlimit_cfg3 cfg = {}; |
818 | int ret; | |
819 | ||
820 | ret = cfg_copy(&cfg, (void *)&info->cfg, 2); | |
bea74641 VP |
821 | if (ret) |
822 | return ret; | |
823 | ||
824 | return hashlimit_mt_common(skb, par, hinfo, &cfg, 2); | |
825 | } | |
826 | ||
827 | static bool | |
828 | hashlimit_mt(const struct sk_buff *skb, struct xt_action_param *par) | |
829 | { | |
830 | const struct xt_hashlimit_mtinfo3 *info = par->matchinfo; | |
831 | struct xt_hashlimit_htable *hinfo = info->hinfo; | |
11d5f157 | 832 | |
bea74641 | 833 | return hashlimit_mt_common(skb, par, hinfo, &info->cfg, 3); |
11d5f157 VP |
834 | } |
835 | ||
8d0015a7 CW |
836 | #define HASHLIMIT_MAX_SIZE 1048576 |
837 | ||
11d5f157 VP |
838 | static int hashlimit_mt_check_common(const struct xt_mtchk_param *par, |
839 | struct xt_hashlimit_htable **hinfo, | |
bea74641 | 840 | struct hashlimit_cfg3 *cfg, |
11d5f157 | 841 | const char *name, int revision) |
09e410de | 842 | { |
e89fc3f1 | 843 | struct net *net = par->net; |
4a5a5c73 | 844 | int ret; |
09e410de | 845 | |
11d5f157 | 846 | if (cfg->gc_interval == 0 || cfg->expire == 0) |
bd414ee6 | 847 | return -EINVAL; |
8d0015a7 CW |
848 | if (cfg->size > HASHLIMIT_MAX_SIZE) { |
849 | cfg->size = HASHLIMIT_MAX_SIZE; | |
850 | pr_info_ratelimited("size too large, truncated to %u\n", cfg->size); | |
851 | } | |
852 | if (cfg->max > HASHLIMIT_MAX_SIZE) { | |
853 | cfg->max = HASHLIMIT_MAX_SIZE; | |
854 | pr_info_ratelimited("max too large, truncated to %u\n", cfg->max); | |
855 | } | |
aa5fa318 | 856 | if (par->family == NFPROTO_IPV4) { |
11d5f157 | 857 | if (cfg->srcmask > 32 || cfg->dstmask > 32) |
bd414ee6 | 858 | return -EINVAL; |
09e410de | 859 | } else { |
11d5f157 | 860 | if (cfg->srcmask > 128 || cfg->dstmask > 128) |
bd414ee6 | 861 | return -EINVAL; |
09e410de JE |
862 | } |
863 | ||
11d5f157 | 864 | if (cfg->mode & ~XT_HASHLIMIT_ALL) { |
b2606644 FW |
865 | pr_info_ratelimited("Unknown mode mask %X, kernel too old?\n", |
866 | cfg->mode); | |
0197dee7 FW |
867 | return -EINVAL; |
868 | } | |
869 | ||
870 | /* Check for overflow. */ | |
bea74641 | 871 | if (revision >= 3 && cfg->mode & XT_HASHLIMIT_RATE_MATCH) { |
90c4ae4e | 872 | if (cfg->avg == 0 || cfg->avg > U32_MAX) { |
b2606644 | 873 | pr_info_ratelimited("invalid rate\n"); |
bea74641 VP |
874 | return -ERANGE; |
875 | } | |
876 | ||
877 | if (cfg->interval == 0) { | |
b2606644 | 878 | pr_info_ratelimited("invalid interval\n"); |
bea74641 VP |
879 | return -EINVAL; |
880 | } | |
881 | } else if (cfg->mode & XT_HASHLIMIT_BYTES) { | |
11d5f157 | 882 | if (user2credits_byte(cfg->avg) == 0) { |
b2606644 FW |
883 | pr_info_ratelimited("overflow, rate too high: %llu\n", |
884 | cfg->avg); | |
0197dee7 FW |
885 | return -EINVAL; |
886 | } | |
11d5f157 | 887 | } else if (cfg->burst == 0 || |
b2606644 FW |
888 | user2credits(cfg->avg * cfg->burst, revision) < |
889 | user2credits(cfg->avg, revision)) { | |
890 | pr_info_ratelimited("overflow, try lower: %llu/%llu\n", | |
891 | cfg->avg, cfg->burst); | |
892 | return -ERANGE; | |
0197dee7 FW |
893 | } |
894 | ||
2eff25c1 | 895 | mutex_lock(&hashlimit_mutex); |
11d5f157 VP |
896 | *hinfo = htable_find_get(net, name, par->family); |
897 | if (*hinfo == NULL) { | |
898 | ret = htable_create(net, cfg, name, par->family, | |
899 | hinfo, revision); | |
4a5a5c73 JE |
900 | if (ret < 0) { |
901 | mutex_unlock(&hashlimit_mutex); | |
902 | return ret; | |
903 | } | |
09e410de | 904 | } |
2eff25c1 | 905 | mutex_unlock(&hashlimit_mutex); |
11d5f157 | 906 | |
bd414ee6 | 907 | return 0; |
09e410de JE |
908 | } |
909 | ||
11d5f157 VP |
910 | static int hashlimit_mt_check_v1(const struct xt_mtchk_param *par) |
911 | { | |
912 | struct xt_hashlimit_mtinfo1 *info = par->matchinfo; | |
bea74641 | 913 | struct hashlimit_cfg3 cfg = {}; |
11d5f157 VP |
914 | int ret; |
915 | ||
b1d0a5d0 FW |
916 | ret = xt_check_proc_name(info->name, sizeof(info->name)); |
917 | if (ret) | |
918 | return ret; | |
11d5f157 VP |
919 | |
920 | ret = cfg_copy(&cfg, (void *)&info->cfg, 1); | |
11d5f157 VP |
921 | if (ret) |
922 | return ret; | |
923 | ||
924 | return hashlimit_mt_check_common(par, &info->hinfo, | |
925 | &cfg, info->name, 1); | |
926 | } | |
927 | ||
bea74641 | 928 | static int hashlimit_mt_check_v2(const struct xt_mtchk_param *par) |
11d5f157 VP |
929 | { |
930 | struct xt_hashlimit_mtinfo2 *info = par->matchinfo; | |
bea74641 VP |
931 | struct hashlimit_cfg3 cfg = {}; |
932 | int ret; | |
933 | ||
b1d0a5d0 FW |
934 | ret = xt_check_proc_name(info->name, sizeof(info->name)); |
935 | if (ret) | |
936 | return ret; | |
bea74641 VP |
937 | |
938 | ret = cfg_copy(&cfg, (void *)&info->cfg, 2); | |
bea74641 VP |
939 | if (ret) |
940 | return ret; | |
941 | ||
942 | return hashlimit_mt_check_common(par, &info->hinfo, | |
943 | &cfg, info->name, 2); | |
944 | } | |
945 | ||
946 | static int hashlimit_mt_check(const struct xt_mtchk_param *par) | |
947 | { | |
948 | struct xt_hashlimit_mtinfo3 *info = par->matchinfo; | |
b1d0a5d0 | 949 | int ret; |
11d5f157 | 950 | |
b1d0a5d0 FW |
951 | ret = xt_check_proc_name(info->name, sizeof(info->name)); |
952 | if (ret) | |
953 | return ret; | |
11d5f157 VP |
954 | |
955 | return hashlimit_mt_check_common(par, &info->hinfo, &info->cfg, | |
bea74641 VP |
956 | info->name, 3); |
957 | } | |
958 | ||
959 | static void hashlimit_mt_destroy_v2(const struct xt_mtdtor_param *par) | |
960 | { | |
961 | const struct xt_hashlimit_mtinfo2 *info = par->matchinfo; | |
962 | ||
963 | htable_put(info->hinfo); | |
11d5f157 VP |
964 | } |
965 | ||
0dc60a45 | 966 | static void hashlimit_mt_destroy_v1(const struct xt_mtdtor_param *par) |
09e410de | 967 | { |
6be3d859 | 968 | const struct xt_hashlimit_mtinfo1 *info = par->matchinfo; |
09e410de JE |
969 | |
970 | htable_put(info->hinfo); | |
971 | } | |
972 | ||
11d5f157 VP |
973 | static void hashlimit_mt_destroy(const struct xt_mtdtor_param *par) |
974 | { | |
bea74641 | 975 | const struct xt_hashlimit_mtinfo3 *info = par->matchinfo; |
11d5f157 VP |
976 | |
977 | htable_put(info->hinfo); | |
978 | } | |
979 | ||
d3c5ee6d | 980 | static struct xt_match hashlimit_mt_reg[] __read_mostly = { |
09e410de JE |
981 | { |
982 | .name = "hashlimit", | |
983 | .revision = 1, | |
ee999d8b | 984 | .family = NFPROTO_IPV4, |
0dc60a45 | 985 | .match = hashlimit_mt_v1, |
09e410de | 986 | .matchsize = sizeof(struct xt_hashlimit_mtinfo1), |
ec231890 | 987 | .usersize = offsetof(struct xt_hashlimit_mtinfo1, hinfo), |
0dc60a45 VP |
988 | .checkentry = hashlimit_mt_check_v1, |
989 | .destroy = hashlimit_mt_destroy_v1, | |
09e410de JE |
990 | .me = THIS_MODULE, |
991 | }, | |
11d5f157 VP |
992 | { |
993 | .name = "hashlimit", | |
994 | .revision = 2, | |
995 | .family = NFPROTO_IPV4, | |
bea74641 | 996 | .match = hashlimit_mt_v2, |
11d5f157 | 997 | .matchsize = sizeof(struct xt_hashlimit_mtinfo2), |
ec231890 | 998 | .usersize = offsetof(struct xt_hashlimit_mtinfo2, hinfo), |
bea74641 VP |
999 | .checkentry = hashlimit_mt_check_v2, |
1000 | .destroy = hashlimit_mt_destroy_v2, | |
1001 | .me = THIS_MODULE, | |
1002 | }, | |
1003 | { | |
1004 | .name = "hashlimit", | |
1005 | .revision = 3, | |
1006 | .family = NFPROTO_IPV4, | |
1007 | .match = hashlimit_mt, | |
1008 | .matchsize = sizeof(struct xt_hashlimit_mtinfo3), | |
1009 | .usersize = offsetof(struct xt_hashlimit_mtinfo3, hinfo), | |
11d5f157 VP |
1010 | .checkentry = hashlimit_mt_check, |
1011 | .destroy = hashlimit_mt_destroy, | |
1012 | .me = THIS_MODULE, | |
1013 | }, | |
c0cd1156 | 1014 | #if IS_ENABLED(CONFIG_IP6_NF_IPTABLES) |
09e410de JE |
1015 | { |
1016 | .name = "hashlimit", | |
1017 | .revision = 1, | |
ee999d8b | 1018 | .family = NFPROTO_IPV6, |
0dc60a45 | 1019 | .match = hashlimit_mt_v1, |
09e410de | 1020 | .matchsize = sizeof(struct xt_hashlimit_mtinfo1), |
ec231890 | 1021 | .usersize = offsetof(struct xt_hashlimit_mtinfo1, hinfo), |
0dc60a45 VP |
1022 | .checkentry = hashlimit_mt_check_v1, |
1023 | .destroy = hashlimit_mt_destroy_v1, | |
09e410de JE |
1024 | .me = THIS_MODULE, |
1025 | }, | |
11d5f157 VP |
1026 | { |
1027 | .name = "hashlimit", | |
1028 | .revision = 2, | |
1029 | .family = NFPROTO_IPV6, | |
bea74641 | 1030 | .match = hashlimit_mt_v2, |
11d5f157 | 1031 | .matchsize = sizeof(struct xt_hashlimit_mtinfo2), |
ec231890 | 1032 | .usersize = offsetof(struct xt_hashlimit_mtinfo2, hinfo), |
bea74641 VP |
1033 | .checkentry = hashlimit_mt_check_v2, |
1034 | .destroy = hashlimit_mt_destroy_v2, | |
1035 | .me = THIS_MODULE, | |
1036 | }, | |
1037 | { | |
1038 | .name = "hashlimit", | |
1039 | .revision = 3, | |
1040 | .family = NFPROTO_IPV6, | |
1041 | .match = hashlimit_mt, | |
1042 | .matchsize = sizeof(struct xt_hashlimit_mtinfo3), | |
1043 | .usersize = offsetof(struct xt_hashlimit_mtinfo3, hinfo), | |
11d5f157 VP |
1044 | .checkentry = hashlimit_mt_check, |
1045 | .destroy = hashlimit_mt_destroy, | |
1046 | .me = THIS_MODULE, | |
1047 | }, | |
7b21e09d | 1048 | #endif |
1da177e4 LT |
1049 | }; |
1050 | ||
1051 | /* PROC stuff */ | |
1da177e4 | 1052 | static void *dl_seq_start(struct seq_file *s, loff_t *pos) |
f4f6fb71 | 1053 | __acquires(htable->lock) |
1da177e4 | 1054 | { |
1286df26 | 1055 | struct xt_hashlimit_htable *htable = PDE_DATA(file_inode(s->file)); |
1da177e4 LT |
1056 | unsigned int *bucket; |
1057 | ||
1058 | spin_lock_bh(&htable->lock); | |
1059 | if (*pos >= htable->cfg.size) | |
1060 | return NULL; | |
1061 | ||
1062 | bucket = kmalloc(sizeof(unsigned int), GFP_ATOMIC); | |
1063 | if (!bucket) | |
1064 | return ERR_PTR(-ENOMEM); | |
1065 | ||
1066 | *bucket = *pos; | |
1067 | return bucket; | |
1068 | } | |
1069 | ||
1070 | static void *dl_seq_next(struct seq_file *s, void *v, loff_t *pos) | |
1071 | { | |
1286df26 | 1072 | struct xt_hashlimit_htable *htable = PDE_DATA(file_inode(s->file)); |
68ad546a | 1073 | unsigned int *bucket = v; |
1da177e4 LT |
1074 | |
1075 | *pos = ++(*bucket); | |
1076 | if (*pos >= htable->cfg.size) { | |
1077 | kfree(v); | |
1078 | return NULL; | |
1079 | } | |
1080 | return bucket; | |
1081 | } | |
1082 | ||
1083 | static void dl_seq_stop(struct seq_file *s, void *v) | |
f4f6fb71 | 1084 | __releases(htable->lock) |
1da177e4 | 1085 | { |
1286df26 | 1086 | struct xt_hashlimit_htable *htable = PDE_DATA(file_inode(s->file)); |
68ad546a | 1087 | unsigned int *bucket = v; |
1da177e4 | 1088 | |
55e0d7cf ED |
1089 | if (!IS_ERR(bucket)) |
1090 | kfree(bucket); | |
1da177e4 LT |
1091 | spin_unlock_bh(&htable->lock); |
1092 | } | |
1093 | ||
11d5f157 VP |
1094 | static void dl_seq_print(struct dsthash_ent *ent, u_int8_t family, |
1095 | struct seq_file *s) | |
1da177e4 | 1096 | { |
39b46fc6 | 1097 | switch (family) { |
ee999d8b | 1098 | case NFPROTO_IPV4: |
11d5f157 | 1099 | seq_printf(s, "%ld %pI4:%u->%pI4:%u %llu %llu %llu\n", |
e71456ae SRRH |
1100 | (long)(ent->expires - jiffies)/HZ, |
1101 | &ent->dst.ip.src, | |
1102 | ntohs(ent->dst.src_port), | |
1103 | &ent->dst.ip.dst, | |
1104 | ntohs(ent->dst.dst_port), | |
1105 | ent->rateinfo.credit, ent->rateinfo.credit_cap, | |
1106 | ent->rateinfo.cost); | |
02e4eb75 | 1107 | break; |
c0cd1156 | 1108 | #if IS_ENABLED(CONFIG_IP6_NF_IPTABLES) |
ee999d8b | 1109 | case NFPROTO_IPV6: |
11d5f157 | 1110 | seq_printf(s, "%ld %pI6:%u->%pI6:%u %llu %llu %llu\n", |
e71456ae SRRH |
1111 | (long)(ent->expires - jiffies)/HZ, |
1112 | &ent->dst.ip6.src, | |
1113 | ntohs(ent->dst.src_port), | |
1114 | &ent->dst.ip6.dst, | |
1115 | ntohs(ent->dst.dst_port), | |
1116 | ent->rateinfo.credit, ent->rateinfo.credit_cap, | |
1117 | ent->rateinfo.cost); | |
02e4eb75 | 1118 | break; |
7b21e09d | 1119 | #endif |
39b46fc6 PM |
1120 | default: |
1121 | BUG(); | |
39b46fc6 | 1122 | } |
11d5f157 VP |
1123 | } |
1124 | ||
bea74641 VP |
1125 | static int dl_seq_real_show_v2(struct dsthash_ent *ent, u_int8_t family, |
1126 | struct seq_file *s) | |
1127 | { | |
1286df26 | 1128 | struct xt_hashlimit_htable *ht = PDE_DATA(file_inode(s->file)); |
bea74641 VP |
1129 | |
1130 | spin_lock(&ent->lock); | |
1131 | /* recalculate to show accurate numbers */ | |
1132 | rateinfo_recalc(ent, jiffies, ht->cfg.mode, 2); | |
1133 | ||
1134 | dl_seq_print(ent, family, s); | |
1135 | ||
1136 | spin_unlock(&ent->lock); | |
1137 | return seq_has_overflowed(s); | |
1138 | } | |
1139 | ||
11d5f157 VP |
1140 | static int dl_seq_real_show_v1(struct dsthash_ent *ent, u_int8_t family, |
1141 | struct seq_file *s) | |
1142 | { | |
1286df26 | 1143 | struct xt_hashlimit_htable *ht = PDE_DATA(file_inode(s->file)); |
11d5f157 VP |
1144 | |
1145 | spin_lock(&ent->lock); | |
1146 | /* recalculate to show accurate numbers */ | |
1147 | rateinfo_recalc(ent, jiffies, ht->cfg.mode, 1); | |
1148 | ||
1149 | dl_seq_print(ent, family, s); | |
1150 | ||
1151 | spin_unlock(&ent->lock); | |
1152 | return seq_has_overflowed(s); | |
1153 | } | |
1154 | ||
1155 | static int dl_seq_real_show(struct dsthash_ent *ent, u_int8_t family, | |
1156 | struct seq_file *s) | |
1157 | { | |
1286df26 | 1158 | struct xt_hashlimit_htable *ht = PDE_DATA(file_inode(s->file)); |
11d5f157 VP |
1159 | |
1160 | spin_lock(&ent->lock); | |
1161 | /* recalculate to show accurate numbers */ | |
bea74641 | 1162 | rateinfo_recalc(ent, jiffies, ht->cfg.mode, 3); |
11d5f157 VP |
1163 | |
1164 | dl_seq_print(ent, family, s); | |
1165 | ||
02e4eb75 | 1166 | spin_unlock(&ent->lock); |
e71456ae | 1167 | return seq_has_overflowed(s); |
1da177e4 LT |
1168 | } |
1169 | ||
bea74641 VP |
1170 | static int dl_seq_show_v2(struct seq_file *s, void *v) |
1171 | { | |
1286df26 | 1172 | struct xt_hashlimit_htable *htable = PDE_DATA(file_inode(s->file)); |
bea74641 VP |
1173 | unsigned int *bucket = (unsigned int *)v; |
1174 | struct dsthash_ent *ent; | |
1175 | ||
1176 | if (!hlist_empty(&htable->hash[*bucket])) { | |
1177 | hlist_for_each_entry(ent, &htable->hash[*bucket], node) | |
1178 | if (dl_seq_real_show_v2(ent, htable->family, s)) | |
1179 | return -1; | |
1180 | } | |
1181 | return 0; | |
1182 | } | |
1183 | ||
0dc60a45 | 1184 | static int dl_seq_show_v1(struct seq_file *s, void *v) |
1da177e4 | 1185 | { |
1286df26 | 1186 | struct xt_hashlimit_htable *htable = PDE_DATA(file_inode(s->file)); |
68ad546a | 1187 | unsigned int *bucket = v; |
1da177e4 | 1188 | struct dsthash_ent *ent; |
1da177e4 | 1189 | |
39b46fc6 | 1190 | if (!hlist_empty(&htable->hash[*bucket])) { |
b67bfe0d | 1191 | hlist_for_each_entry(ent, &htable->hash[*bucket], node) |
0dc60a45 | 1192 | if (dl_seq_real_show_v1(ent, htable->family, s)) |
683a04ce | 1193 | return -1; |
39b46fc6 | 1194 | } |
1da177e4 LT |
1195 | return 0; |
1196 | } | |
1197 | ||
11d5f157 VP |
1198 | static int dl_seq_show(struct seq_file *s, void *v) |
1199 | { | |
1286df26 | 1200 | struct xt_hashlimit_htable *htable = PDE_DATA(file_inode(s->file)); |
68ad546a | 1201 | unsigned int *bucket = v; |
11d5f157 VP |
1202 | struct dsthash_ent *ent; |
1203 | ||
1204 | if (!hlist_empty(&htable->hash[*bucket])) { | |
1205 | hlist_for_each_entry(ent, &htable->hash[*bucket], node) | |
1206 | if (dl_seq_real_show(ent, htable->family, s)) | |
1207 | return -1; | |
1208 | } | |
1209 | return 0; | |
1210 | } | |
1211 | ||
0dc60a45 | 1212 | static const struct seq_operations dl_seq_ops_v1 = { |
1da177e4 LT |
1213 | .start = dl_seq_start, |
1214 | .next = dl_seq_next, | |
1215 | .stop = dl_seq_stop, | |
0dc60a45 | 1216 | .show = dl_seq_show_v1 |
1da177e4 LT |
1217 | }; |
1218 | ||
bea74641 VP |
1219 | static const struct seq_operations dl_seq_ops_v2 = { |
1220 | .start = dl_seq_start, | |
1221 | .next = dl_seq_next, | |
1222 | .stop = dl_seq_stop, | |
1223 | .show = dl_seq_show_v2 | |
1224 | }; | |
1225 | ||
11d5f157 VP |
1226 | static const struct seq_operations dl_seq_ops = { |
1227 | .start = dl_seq_start, | |
1228 | .next = dl_seq_next, | |
1229 | .stop = dl_seq_stop, | |
1230 | .show = dl_seq_show | |
1231 | }; | |
1232 | ||
e89fc3f1 AD |
1233 | static int __net_init hashlimit_proc_net_init(struct net *net) |
1234 | { | |
1235 | struct hashlimit_net *hashlimit_net = hashlimit_pernet(net); | |
1236 | ||
1237 | hashlimit_net->ipt_hashlimit = proc_mkdir("ipt_hashlimit", net->proc_net); | |
1238 | if (!hashlimit_net->ipt_hashlimit) | |
1239 | return -ENOMEM; | |
c0cd1156 | 1240 | #if IS_ENABLED(CONFIG_IP6_NF_IPTABLES) |
e89fc3f1 AD |
1241 | hashlimit_net->ip6t_hashlimit = proc_mkdir("ip6t_hashlimit", net->proc_net); |
1242 | if (!hashlimit_net->ip6t_hashlimit) { | |
ece31ffd | 1243 | remove_proc_entry("ipt_hashlimit", net->proc_net); |
e89fc3f1 AD |
1244 | return -ENOMEM; |
1245 | } | |
1246 | #endif | |
1247 | return 0; | |
1248 | } | |
1249 | ||
1250 | static void __net_exit hashlimit_proc_net_exit(struct net *net) | |
1251 | { | |
32263dd1 | 1252 | struct xt_hashlimit_htable *hinfo; |
32263dd1 VL |
1253 | struct hashlimit_net *hashlimit_net = hashlimit_pernet(net); |
1254 | ||
b4ef4ce0 SP |
1255 | /* hashlimit_net_exit() is called before hashlimit_mt_destroy(). |
1256 | * Make sure that the parent ipt_hashlimit and ip6t_hashlimit proc | |
1257 | * entries is empty before trying to remove it. | |
32263dd1 VL |
1258 | */ |
1259 | mutex_lock(&hashlimit_mutex); | |
b67bfe0d | 1260 | hlist_for_each_entry(hinfo, &hashlimit_net->htables, node) |
b4ef4ce0 | 1261 | htable_remove_proc_entry(hinfo); |
32263dd1 VL |
1262 | hashlimit_net->ipt_hashlimit = NULL; |
1263 | hashlimit_net->ip6t_hashlimit = NULL; | |
1264 | mutex_unlock(&hashlimit_mutex); | |
1265 | ||
ece31ffd | 1266 | remove_proc_entry("ipt_hashlimit", net->proc_net); |
c0cd1156 | 1267 | #if IS_ENABLED(CONFIG_IP6_NF_IPTABLES) |
ece31ffd | 1268 | remove_proc_entry("ip6t_hashlimit", net->proc_net); |
e89fc3f1 AD |
1269 | #endif |
1270 | } | |
1271 | ||
1272 | static int __net_init hashlimit_net_init(struct net *net) | |
1273 | { | |
1274 | struct hashlimit_net *hashlimit_net = hashlimit_pernet(net); | |
1275 | ||
1276 | INIT_HLIST_HEAD(&hashlimit_net->htables); | |
1277 | return hashlimit_proc_net_init(net); | |
1278 | } | |
1279 | ||
1280 | static void __net_exit hashlimit_net_exit(struct net *net) | |
1281 | { | |
e89fc3f1 AD |
1282 | hashlimit_proc_net_exit(net); |
1283 | } | |
1284 | ||
1285 | static struct pernet_operations hashlimit_net_ops = { | |
1286 | .init = hashlimit_net_init, | |
1287 | .exit = hashlimit_net_exit, | |
1288 | .id = &hashlimit_net_id, | |
1289 | .size = sizeof(struct hashlimit_net), | |
1290 | }; | |
1291 | ||
d3c5ee6d | 1292 | static int __init hashlimit_mt_init(void) |
1da177e4 | 1293 | { |
39b46fc6 | 1294 | int err; |
1da177e4 | 1295 | |
e89fc3f1 AD |
1296 | err = register_pernet_subsys(&hashlimit_net_ops); |
1297 | if (err < 0) | |
1298 | return err; | |
d3c5ee6d JE |
1299 | err = xt_register_matches(hashlimit_mt_reg, |
1300 | ARRAY_SIZE(hashlimit_mt_reg)); | |
39b46fc6 PM |
1301 | if (err < 0) |
1302 | goto err1; | |
1da177e4 | 1303 | |
39b46fc6 PM |
1304 | err = -ENOMEM; |
1305 | hashlimit_cachep = kmem_cache_create("xt_hashlimit", | |
1306 | sizeof(struct dsthash_ent), 0, 0, | |
20c2df83 | 1307 | NULL); |
1da177e4 | 1308 | if (!hashlimit_cachep) { |
b167a37c | 1309 | pr_warn("unable to create slab cache\n"); |
39b46fc6 | 1310 | goto err2; |
1da177e4 | 1311 | } |
e89fc3f1 AD |
1312 | return 0; |
1313 | ||
39b46fc6 | 1314 | err2: |
d3c5ee6d | 1315 | xt_unregister_matches(hashlimit_mt_reg, ARRAY_SIZE(hashlimit_mt_reg)); |
39b46fc6 | 1316 | err1: |
e89fc3f1 | 1317 | unregister_pernet_subsys(&hashlimit_net_ops); |
39b46fc6 | 1318 | return err; |
1da177e4 | 1319 | |
1da177e4 LT |
1320 | } |
1321 | ||
d3c5ee6d | 1322 | static void __exit hashlimit_mt_exit(void) |
1da177e4 | 1323 | { |
d3c5ee6d | 1324 | xt_unregister_matches(hashlimit_mt_reg, ARRAY_SIZE(hashlimit_mt_reg)); |
e89fc3f1 | 1325 | unregister_pernet_subsys(&hashlimit_net_ops); |
02e4eb75 | 1326 | |
c8d1da40 | 1327 | rcu_barrier(); |
02e4eb75 | 1328 | kmem_cache_destroy(hashlimit_cachep); |
1da177e4 LT |
1329 | } |
1330 | ||
d3c5ee6d JE |
1331 | module_init(hashlimit_mt_init); |
1332 | module_exit(hashlimit_mt_exit); |